Process for manufacturing lubricating oil



Sept. 1, 1931. E. M. CLARK PROCESS FOR MANUFACTURING LUBRICATING OIL Filed Jan. 22, 1927 Patented Sept. l, 1931 UNITED .STATES PATENT OFFICE EDGAR M. OLARK, OF NEW YORK, N. Y., ASSIGNOR TO STANDARD OIL DEVELOPMENT COMPANY, A CORPORATION OF DELAWARE PROCESS FOR MANUFACTURING LUBRICATING OIL Appneation inea 'January 22,A 1927. serm No. 162,727.

Q izing tempera-ture in a pipe still or heating coil, introducing the hot oil into a fractionating tower in which the oil vaporizes, treating the hot lubricating oil condensate formed in the tower, and vacuum-distilling the hot L!!! treated oil.

The invention will be fully understood from the following description, read in connection with the accompanying drawing, in which the igure is a diagrammatic perspective view of equipmentl for practicing the process.

Referring to the drawing, reference numerals 1, 2, 3, and 4 denote a battery of seriesconnected stills, into the lirst of which charging stock is passed through a pipe 5. Vapor lines 6 are connected to the stills. A pipe 7 having a valve 8 conveys the residue of lubricating oil in the last still 4 to branch pipes 9 and 10 and pumps 9a and 10, which forward the oil to pipe stills or heating coils 11 and 12. Steam pipes 11"and 12 connect with the coils. From the'coils the oil passes through pipes 13 and 14, respectively, into the lower chambers of the fractionating towers 15 and 16. 'These pipes should be lagged to prevent substantial loss ofv heat. Vapor lines 19 lead from the tops of the towers and are in circuit with a barometric condenser 17 and vacuum pump 18.

A cooling coil 20 is located in the upper portion of the tower 15. A pan 21 collects condensate, which flows through pipe 22 to a treating tank 23, having a steam vent 23. A drain pipe 23 leads from the tank 23 for conducting off excess alkali solution. Bell cap plates 20', or other equipment for fractionation or preventing entrainment, are preferably provided between the inlet to the tower and the pan 21. A bellv cap plate 20 may be placed between the top of the tower and the cooling coil 20. Care should be taken not to impose much resistance to vapor How anywhere in the tower, since high vacuum is usually desired. A steam pipe 24 leads into the bottom ofthe tower 15 and is connected to a spray head 25. A drawoii pipe 26 having a valve 27 is provided at the lower part of the tower. The towers 15 and 16 are equipped in the same way. A branched pressure equalizing line 23 connects the tank 23 with the upper part of the towers.

From the treating tank 23 the oil passes through pipe 28, valve 29, and branch pipes 30 and 31, respectively, into the stills 32 and 33. These stills have towers 34 and 35 from which vapor lines 36 and 37 lead to a condenser 38. A drum 39 receives liquid from the condenser. Reduced pressure is maintained on the system by a vacuum pump 40. A drawoif line 41 and pump 42 are connected to the drum 39.

Valves 9 and 10 are installed respectivel in branch pipes 9 and 10, and valves 19', an 19" in the pipes 19. Valves 30 and 31 are placed in branch pipes 30 and 31, and valves 36 and 37 in the pipes 36 and 37.

The operation of the improved process in a preferred form isl as follows:

A crude oil suitable for the production of lubricants, in this example Colombian crude, is charged into the first still 1 through the pipe 5 and iiows through the series of stills. Light naphtha, gasoline, kerosene, and gas oil are taken oi successively. The lubrieating oil bottoms remaining in the last still 4 will ordinarily be about 45% of the crude charged. These bottoms are passed through pipes 7, 9, and 10 into the heating coils 11 and 12. In these coils the oil is heated to a temperature at which the lubricating constituents tend to vaporize, for example around 800- F. The hot oil is discharged without substantial loss of heat directly into the frac tionating towers 15 and 16 through pipes 13 and 14. Steam is preferably injected through pipes 11 and 12 to increase the velocity of flow through the coils.

Both coils and both towers are used in large scale operation, since eiective heating and vaporization of the oil is best accomplished in this way. However, either heating coil 11 and tower 15, or heating coil 12 and tower 16, may be used if desired. Valves 9', 10', 19',

and 19 will be adjusted to shut olf the coil and tower not in use.

Steam may be injected into the bottom of each tower through pipe 24 and spray head 5 25, to aid in the'distillation of the oil. The absolute pressure in the towers corresponds to about 25 mm. of mercury, in the preferred o eration, but this pressure may be varied. nder the conditions stated, the lubricatlng oil constituents entering the towers are vaporized for the most part and pass up through the baille means into contact with the cooling coils 20. These 'should be regulated so as to avoid cooling the lubricating oil much 15 below its condensation tem erature. The

heav residue is withdrawn rom the towers t rough pipes 26, when required.

Steam and light vapors pass through the ipes 19, substantially all the lubricatlng oil v v zo being condensed in the towers and caught in the pans 21. It is discharged from the pans v without substantial heat loss into the treating tank or agitator 23. The temperature of the oil may be about 500 F. when it enters the v tank 23. In this it is thoroughly mixed with a treating agent, preferably an alkali solu tion. Sodium hydroxide solution of about 33 B. strength is bestA for most purposes. The treating should be continued until all '30 the organic acidity of the oil is neutralized. The oil may leave the tank 23 at about 27 4 F. Animportant feature of the process is the `treatment of the lubricating oil while hot. In'this way heat losses are avoided and a better product is obtained. Very heavy lubricating oils can be made with particular :advantage according to this method.

The treated oil is passed then through the pipe 28 and branch pipes 30 and 31 into the stills 32 and 33, which are fired moderately, care being taken not to crack the oil. These stills are preferably run without steam and maintained under a suitable high vacuum, for example, an absolute pressure corresponding to about 15 mm, of mercury. Lubricating oil is taken off through the vapor lines 36 and 37, condensed in the coil 38, and collected in the tank 39. Either of the stills 32 and 33 maybe used alone, if desired. In such case, valves 31', 36', and 37 will be adjusted to shut of the still not in use. If two different lubricating oil fractions are to be produced, the' stills .3 2 and 33 may be con? nected in series.

It is feasible to operate the towers 15 and 16 at atmospheric pressure with the supply of large amounts of steam. Reduced pressure operation is preferable. Steam may be used 1n the nal stills 32 and 33 and the pressure reduction correspondingly lessened.

.Various changesand alternative arrangements in the described process and apparatus ma be made within the scope of the ap- $6 pende claim, in which it is my intention to claim all novelty inherent in the invention as broadly as the prior art permits. I claim:

In the manufacture oflubricating oils, the

improvement thatcomprises heating a lubricatmg o1l fraction to a vaporizlng temperature, passing the hot oil into a fractionating y zone maintained at an absolute pressure corresponding to about 25 mm. of mercu in- In testimony that I claim the foregoing as my invention, I aix my si ature. l

. EDG M. CLARK. 

